.nav{
	width: 100%;
	height: 70px;
	position: relative;
	top: 0;
	box-shadow: 0 5px 20px rgba(0, 0, 0, 0.5);
	border-radius: 10px;
	background-color: rgb(0, 0, 0);
}
.nav ul{
	width: 100%;
	height: 100%;
	display: flex;
	align-items: center;
	right: 5%;
}
.nav ul .nav-box{
	position: absolute;
	bottom: 0;
	left: 0;
	width: calc((100% / 4)*1);
	height: 10px;
	border-radius: 2px;
	transition: .5s;
}
.nav ul li{
	width: 100%;
	text-align: center;
}
.nav ul li a{
	color: rgb(255, 255, 255);
	font: 100 30px '优设标题黑';
	display: block;
	width: 100%;
	height: 100%;
	line-height: 70px;
}.nav ul li:nth-child(1):hover~.nav-box{
	left: calc(100% / 4 *0);
	background-color: rgb(77, 59, 218);
}
.nav ul li:nth-child(2):hover~.nav-box{
	left: calc(100% / 4 *1);
	background-color: red;
}
.nav ul li:nth-child(3):hover~.nav-box{
	left: calc(100% / 4 *2);
	background-color: #ee8930;
}
.nav ul li:nth-child(4):hover~.nav-box{
	left: calc(100% / 4 *3);
	background-color: #17cfe8;
}
#text-photo{
    text-align: center;
}
#text-main{
	text-align: center;
	color: white;
	margin:100px;
	font-size: 30px;
	font-weight: 80;
	letter-spacing: 5px;
}
